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Java Collections fill() Method with Example

Collections Class fill() method: Here, we are going to learn about the fill() method of Collections Class with its syntax and example.
Submitted by Preeti Jain, on February 03, 2020

Collections Class fill() method

• fill() method is available in java.util package.
• fill() method is used to fill all the elements in the given list(l) with the given element (ele).
• fill() method is a static method, so it is accessible with the class name and if we try to access the method with the class object then also we will not get an error.
• fill() method may throw an exception at the filling the list with the given element.
  UnsupportedOperationException: This exception may throw when the given parameter List(l) un-support set operation.

Syntax:

    public static void fill(List l, Type ele);

Parameter(s):

• List l – represents the list object to be filled with given element(ele).
• Type ele – represents the element(ele) with which to replace the elements in the list.

Return value:

The return type of this method is void, it returns nothing.

Example:

// Java program is to demonstrate the example
// of void fill() of Collections

import java.util.*;

public class Fill {
    public static void main(String args[]) {
        // Instantiate a LinkedList   
        List link_l = new LinkedList();

        // By using add() method is to
        // add elements in linked list
        link_l.add(10);
        link_l.add(20);
        link_l.add(30);
        link_l.add(40);
        link_l.add(50);

        // Display LinkedList
        System.out.println("link_l: " + link_l);

        // By using fill() method is to
        // fill the linked list with the
        // given element "100"
        Collections.fill(link_l, 100);

        //Display LinkedList
        System.out.println("Collections.fill(link_l,100): " + link_l);
    }
}

Output

link_l: [10, 20, 30, 40, 50]
Collections.fill(link_l,100): [100, 100, 100, 100, 100]